About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
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Tackling Structural Materials Challenges for Advanced Nuclear Reactors
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Presentation Title |
Mechanistic Calculation of the Effective Silver Diffusion Coefficient in Polycrystalline Silicon Carbide: Application to Silver Release in AGR-1 TRISO Particles |
Author(s) |
Pierre-Clement A. Simon, Larry K. Aagesen, Chao Jiang, Wen Jiang, Jia-Hong Ke |
On-Site Speaker (Planned) |
Pierre-Clement A. Simon |
Abstract Scope |
The silicon carbide (SiC) layer in tristructural isotropic (TRISO) fuel particles serves as a barrier to prevent the escape of fission from the fuel kernel. The release of silver (Ag) is a concern due to the long half-life of the 110mAg isotope. In this study, the effective diffusion coefficient of the fission product Ag through the grain boundary (GB) network is calculated using a combination of atomistic and phase-field methods. Atomistic calculations of Ag diffusivity in SiC bulk and GBs are leveraged to develop a mesoscale effective Ag diffusion coefficient (Deff) in SiC. Since GBs serve as pathways for Ag diffusion, Deff is defined as a function of temperature, microstructure variables, and fluence. Deff is implemented in the fuel performance code Bison to predict Ag release from AGR-1 TRISO fuel particles. We hereby quantify the impact of SiC grain size and irradiation on Ag release and improve Bison's predictions. |